Install the Level 3 surge protection device inside the equipment or at the equipment's power supply input, especially for critical or sensitive electronic devices. Technical Requirements Maximum discharge capacity: 20kA per phase or lower. Voltage protection level: ≤ 1800V. The 18th Edition of BS 7671 saw a number of significant changes to the requirements for provision of surge protection devices (SPDs). According to the principle of graded lightning protection, and based on the likelihood of a building being struck by lightning, it is necessary to deploy surge protector against lightning in stages to. SPD) is required to be installed on dwelling unit services. A study commissioned by the Fire Protection Research Foundation found t sonnel against. For all other cases SPDs shall be fitted to protect against transient overvoltages, unless the owner of the installation declines such protection and wishes to accept the risk of damage to both wiring and equipment as tolerable. This will mean that any distribution board supplying electrical. Indent three is similar to the previous requirement where an SPD should be installed where commercial or industrial activity could be interrupted, the requirement now is that an SPD shall be provided where the consequence caused by overvoltage could result in significant financial or data loss. Understanding where, when, and how SPDs are required.
